What are some alternatives?
When comparing Scrollout F1 and Proxmox Mail Gateway, you can also consider the following products
MailScanner - MailScanner is a open source email security system design for Linux-based email gateways.
SpamAssassin - Use this program to "Unspam" your mailbox(es).
Mailwasher - Over 8 million people use MailWasher as their spam filter
Kolab Community - Kolab Groupware is a secure, scalable, reliable, flexible, full-featured collaboration suite.
BitNinja.io - BitNinja is the first integrated server defense network, can be installed within 1 minute on any...
Barracuda Email Security Gateway - Barracuda's Email Security Gateway is a powerful antivirus filter specifically designed to identify and eliminate email-borne threats, stopping hazards before they reach the network.